In addition to the videos, Dunn will also have teachers go through hallways and throw items at them to distract them.

"If you can't handle that type of situation, you definitely are not in line with carrying a gun in a school," Dunn said.

It's training Harrold Independent School District in North Texas uses.

"I think that they feel better about what they're doing," Harrold ISD superintendent David Thweatt said.

Thweatt said it helps teachers become accurate and mentally focused.

"I don't care if I know them. If they are in the act of killing other innocent people they are probably going to override my thought process about who they are or my relationship with them," Thweatt said.

Getting educators in the right mindset is what Dunn is passionate about.

A simulation he hopes will help teachers eliminate suspects.

"They're wolves looking for sheep, and I train sheepdogs," Dunn said.

In addition to schools, the company also works with churches and recently hospitals.